title: Matrix solid-phase dispersion extraction of organophosphorus pesticides from propolis extracts and recovery evaluation by GC/MS.
abstract: Five organophosphorus pesticides (dichlorvos, diazinon, malathion, methyl parathion and coumaphos) were extracted from propolis by matrix solid-phase dispersion (MSPD) extraction using octadecylsilica (C18, 1.0 g) as dispersant material. The kind of solvent elution (acetonitrile or ethyl acetate), volume (8 mL and 15 mL), and adsorbent used to clean-up the extracts (graphitized carbon, florisil™ and silica) were optimized using fortified propolis samples (5.0 μg g(-1)). Recovery was determined by gas chromatography with mass spectrometric detection in selected ion monitoring mode (GC/MS-SIM) and statistical analysis was done to determine better extraction conditions. Relatively high recovery and lower relative standard deviation values (3.1-14.6%) were obtained when analytes were eluted with ethyl acetate from the MSPD column. Diazinon, malathion, methyl parathion, and coumaphos show recoveries of 72.7%, 84.6%, 62.6%, and 78.3%, respectively. In contrast, the recovery for dichlorvos was 53.8%. Additional adsorbents tested for clean-up and increase in solvent elution did not affect recoveries positively and caused a high background in chromatograms. Thus, final conditions were 1 mL of sample, 1 g C18 and 8 mL of ethyl acetate.
authors.affiliation: Facultad de Ingeniería Química, Universidad Autónoma de Yucatán, Tablaje catastral, Colonia Chuburná de Hidalgo Inn, CP, Mérida, Yucatán, Mexico.
authors.forename: Gloria M
authors.initials: GM
authors.lastname: Acosta-Tejada
authors.forename: Salvador
authors.initials: S
authors.lastname: Medina-Peralta
authors.forename: Yolanda B
authors.initials: YB
authors.lastname: Moguel-Ordóñez
authors.forename: David
authors.initials: D
authors.lastname: Muñoz-Rodríguez
mesh_terms: D000327:Adsorption; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D009943:Organophosphorus Compounds / Q000737:chemistry / Q000302:isolation & purification*; D010575:Pesticides / Q000737:chemistry / Q000302:isolation & purification*; D011429:Propolis / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000379:methods*; D012997:Solvents
chemical_list: D009943:Organophosphorus Compounds; D010575:Pesticides; D012997:Solvents; D011429:Propolis